(Reuters Health) – Many outcomes for hospital patients – including how long they stay and their survival odds after they go home – may depend on whether they’re cared for by their primary care physician or another type of doctor, a U.S. study suggests.

Researchers examined data on 560,651 admissions nationwide for patients covered by Medicare, the U.S. health program for the elderly and disabled, who had a variety of common medical problems. Their hospital care was overseen by one of three types of general medicine doctors: their primary care physician, a so-called hospitalist with special training in caring for hospitalized patients, or other generalists.

Compared to patients seen by hospitalists, patients seen by their primary care physicians had more specialist consultations and longer hospital stays, which can sometimes indicate less efficient care. But these patients were also more likely to be discharged home instead of a rehab or nursing facility, and they were also less likely to die within 30 days of leaving the hospital.

“It’s possible that primary care physicians aren’t willing to discharge until they feel like there’s a more ideal plan for home, and that hospitalists are discharging earlier, when people are medically stable, with the assumption that outpatient providers will work on further refining the care plan,” said lead study author Dr. Jennifer Stevens of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston.

The difference in survival outcomes is harder to explain, Stevens said by email.

“We don’t know whether it’s because of something that happens in the hospital as a result of the primary care physician’s decisions, or because of how a primary care physician’s presence in the hospital influences post-hospital care,” Stevens added.

Hospitalists now outnumber any other specialty in internal medicine and they care for approximately three in every four patients in U.S. hospitals, researchers note in JAMA Internal Medicine.

The hospitalist model of care has taken hold in recent years as a way to shepherd increasingly complex patients with multiple serious and chronic health problems through hospital stays. Because they know how things work inside the hospital, they can expedite tests, coordinate specialist consultations, and work to improve both the efficiency and quality of care.

For the current study, researchers wanted to see if patient outcomes were different with hospitalists than with a primary care physician or another general medicine doctor that the patient didn’t already know.

Hospitalists cared for 60 percent of patients in the study, while primary care physicians saw 14 percent of the patients and other generalists treated 26 percent of the patients.

Compared to hospitalists, primary care physicians used consultations 3 percent more often and other generalists used consultations 6 percent more often, the study found.

Lengths of hospital stays were also 12 percent longer with primary care physicians and 6 percent longer with other generalists than they were with hospitalists.

Primary care physicians were 14 percent more likely than hospitalists to discharge patients to their homes instead of institutional care settings, while generalists were 6 percent less likely than hospitalists to do this.

Readmissions, or repeat hospitalizations, within one week or one month of discharge were similar for primary care physicians and hospitalists, but happened more often with other generalists.

Patients cared for by primary care physicians were 6 percent less likely to die within 30 days of discharge than people treated by hospitalists. But with generalists, patients were 9 percent more likely to die than with primary care physicians.

The study wasn’t a controlled experiment designed to prove whether or how the type of doctor treating hospital patients influences outcomes.

“This does not show that the hospitalist model does not work,” said Dr. Seth Landefeld, author of an accompanying editorial and a researcher at the University of Alabama at Birmingham.

But it does suggest there are benefits to sticking with one doctor.

“A trusting relationship with a doctor who will `orchestrate’ your care through the course of illness can be very valuable, rather than bouncing from one subspecialist to another without a `conducting’ doctor,” Landefeld said by email.